Previously, we have talked about all things being an object in Javascript. But to what extent can we apply this to our beloved functions. You can see this almost everywhere with the below syntax - 1 2 3 4 5 6 const getSum = (x, y) => { return x + y; }; console.

What are generators and how can I use them? How do you write loops in Javascript - Simple for/while? Recursion? In other less exciting ways? How do you throttle and control function execution? Debounce function? Build your own? What if you could produce the right mix of reusable functions, looping and throttling in one go?

Is there really a problem with NPM use? Short answer: no. Long answer: it’s complicated. I am nothing but thankful for the tonnes of NPM packages. I would never have built web applications that could support thousands of users all by myself without all those hundreds of packages. There are thousands of developers (if not millions) who do much better than what I could.

Flatten recursive arrays using Array.flat(). We have seen how to flatten arrays before. Array.flat() is quite useful to flatten arrays in one statement and output a simpler array. But, what about situations where you do not know the depth of array hierarchy - 1 const nums = [[1, 2], [3, 4], [[5], [6]], [[[7]]]]; Fear not.

Remember to filter your arrays before doing array-wise operation. Filtering falsy values must be the first operation even if you do not have specific filtering requirements. Consider this array - 1 const nums = [1, 3, 5, undefined, 7, 9, null]; If you are in control of the data source, you can very well expect to filter only when necessary.

Can you use the Date object without brackets? Yes, apparently - to a friend’s delight and my chagrin. I should know better than to rely on my somewhat shaky Javascript knowledge. This is the format for a sane Date code.. 1 2 3 const today = new Date(); console.log(today); // 2019-08-23T09:31:12.

Load external scripts asynchronously in Javascript. We have seen about loading functions asynchronously in Javascript. But, what about the scripts that you load from other files, CDNs or other external sources You can do a simple async to load scripts without impacting the loading speed as perceived by the user.

Arguments object throws an error when used with arrow functions. Consider this code - 1 2 3 4 5 6 function getSum() { return arguments[0] + arguments[1]; } console.log(getSum(1, 2)); // 3 The result is as expected. But, you cannot do the same using an arrow function.

One of the interesting projects that I came across recently was NodeGUI. NodeGUI describes itself as an enabler to build cross-platform desktop applications using Javascript (and React) and Qt5. Using NodeGUI, you should be able to - Create desktop applications that run on Windows, Linux or MacOS Styling with CSS Support for desktop events that are listenable from Qt Lower CPU/memory footprint Of course, the comparison with Electron is evident.

Concatenating strings is a fairly simple affair. 1 2 console.log("hello" + " world"); // hello world This works because Javascript figures out the types, thinks that adding strings is not an intelligent thing to do, and therefore, concatenates the two strings. However, it may lead to problems.

Let’s create a simple ‘to do’ application using Svelte and GraphQL. The objective is to demonstrate getting started on a GraphQL query and insert operation in a Svelte component. If you are new to Svelte, you may want to go over what Svelte can do from the official site, or see Svelte quick overview.

The typical Javascript frameworks love playing the middleman. They continue playing that role at development and at run time. Svelte is not your typical middleman - instead the framework lays out the path during build, and completely hands over to standard Javascript at runtime. If that does not pick your interest - I don’t know what will 😜.

Beware of these null check gotchas. Consider this code - 1 2 3 4 5 6 7 const sum = null; if (sum) { console.log("valid sum"); } // nothing printed The above code shows expected behaviour. Nothing is printed since if(sum) returns false. Now, try the code below.